Weather report: Tropical moisture spreads over most of the U.S.

In the West, isolated thunderstorms linger in the northern Great Basin and parts of Arizona and New Mexico. Some of the storms are producing lightning and gusty winds but little rain, sparking new fires and hampering wildfire containment efforts. In addition, record-setting heat persists in parts of California, the Great Basin, and the Northwest.

On the Plains, mostly dry weather continues. Favorably cool conditions prevail on the drought-stricken central and southern High Plains, although rain is still needed. Meanwhile on the northern High Plains, hot weather is promoting hard red winter wheat maturation and the development of spring-sown crops.

In the Corn Belt, a few showers linger across southern and eastern portions of the region, slowing soft red winter wheat harvesting but benefiting corn and soybeans. Elsewhere, mild, dry weather is easing flooding in previously waterlogged sections of the upper Midwest.

In the South, tropical moisture continues to stream northward from the eastern Gulf Coast region. As a result, the threat of heavy rain and flash flooding persists in parts of the Southeast. In contrast, dry weather prevails from the Mississippi Delta westward.

Outlook: A continuous southerly fetch of tropical moisture will maintain locally heavy showers and thunderstorms from the central and eastern Gulf Cost into the Ohio Valley and Mid-Atlantic. Additional rainfall of 2 to 6 inches is possible from Louisiana to western Florida, and northward into the southern Appalachians and Tennessee Valley. Meanwhile, a stalled upper-air low will maintain occasional showers across the central and western Corn Belt. Record-setting heat will gradually ease across the West, accompanied by a gradual increase in monsoon showers. Warmer weather will return to the nation’s mid-section by week’s end, while 90-degree heat develops across the East. The NWS 6- to 10-day outlook for July 8-12 calls for above-normal temperatures in much of the East and West, while cooler-than-normal conditions will be confined to the northern and central Plains and the western Corn Belt. Meanwhile, near- to above-normal rainfall across the majority of the U.S. will contrast with drier-than-normal weather in the Northwest and along the southern Atlantic Coast.